关键词: 储气库, 复杂井筒, 长落鱼电泵打捞, 膨胀管磨铣, 套管段铣, 老井处置

Abstract: Gas storage is the core infrastructure for natural gas peak shaving, supply guarantee and energy security. Aiming at the complex wellbore problems in the reconstruction of oil reservoirs into gas storage, such as casing deformation and damage, falling object sticking, substandard caprock cementing quality and insufficient reliability of reservoir plugging, this paper studies the key technologies and supporting tools for wellbore disposal, and constructs three technical systems: electric submersible pump (ESP) fishing for long fish in high-deviated wells, expansion pipe casing milling disposal, and high-efficiency section milling of long casing sections. An integrated disposal scheme is formed through the optimal design of special fishing tools, scientific assembly of fishing strings and accurate analysis of fish top morphology. The high-efficiency split pilot milling shoe adopts a multi-channel circulation structure and reasonable cutting taper, which significantly improves the operation safety of channel making in high-deviated wells. The six-blade section mill cooperates with the reaming technology, and optimizes the blade geometric parameters and arrangement, effectively improving the section milling efficiency and cutting quality. Field application results show that from 2020 to 2025, the technical system has successfully disposed 8 complex wells in Jidong Oilfield gas storage, with a 100% construction success rate, an average reduction of 32% in operation period, a reduction of more than 90% in sticking risk and a reduction of 28% in construction cost. It realizes safe, efficient and low-cost disposal of complex wellbores, and can provide technical support and engineering reference for the disposal of old wells in similar oil reservoirs reconstructed into gas storage.

Key words: gas storage, complex wellbore, long-fish ESP fishing, expansion pipe milling, casing section milling, old well abandonment